Method of attaching soles to shoes



June 16, 1936.

M. W. TETLOW METHOD OF ATTACHING SOLES TO SHOES Filed Dec. 7, 1932 piece and the shoe bottom and is converted into f Patented June 16, 1936 Max W. Tetlow, Boston, Mass., assignor to United Shoe Machinery Corporation, Paterson, N. L, a corporation of New Jersey Application December 7, 1932, Serial No. 646,157

33 Claims.

This invention relates to improvements in methods of attaching soles to shoes, and to improvements in shoes and shank pieces therefor.

Considerable diiiiculty has been experienced,

.5 particularly in the manufacture of shoes havin cement-attached soles, in securing satisfactory attachment of the tread soles in the shank portions of the shoes and. various attempts have been made to provide for additionalsecurity of i attachment in that locality.

One object of the present invention is to improve the attachment of soles at the shank'portions of shoes.

with this object in view, the invention pro-' vides an improved method of sole attaching which, as herein exemplified, contemplates securing together the intramarginal shank portion of a tread sole and a shank piece attached to the bottom of a shoe by means of cement produced by the action of a solvent upon fibrous material, for

example fibrous cellulose derivative, applied between the tread sole and the shank piece. Preferablv, and .as illustrated herein, fibrous cellulose derivativeis applied also between the shank cement by the action of a solvent to secure the shank piece to the shoe bottom as well as to'the tread sole. As herein exemplified, acetone is employed as the solvent andthe fibrous, cellulose 'ggderivative consists of textile fabric composed of cellulose ester fibers, for example cellulose acetate fibers, the fabric being madein the ,torm ofa tubular sheath-like covering which is to fit the shank piece=and which is slipped 5:= 'ove"r'the latter before it is applied to the shoe.

7 "linsteadvoif being braided, the fibrous covering material may be woven, knitted, felted or otherwise formed and, as illustrated, the material is loosely fabricated so as to provide an absorbent 43 fabric, 1. e., a fabric which is readily soluble, for

example, in acetone or other commercially available. org nic solvent. If desired, also, the coverlng material may be reinforced with fibers, for example cotton fibers, which are insoluble in or '13 inert with respect to the solvent which is' used.

In accordaneejwithpne method of carrying out the invention a covered shank piece is first dipped in a solvent'so as to soften-the cellulose derivative covering and render .it plastic and 50 thereafter the shank piece is positioned upon the shoe bottom and an outside is cement-attached in the usual manner, the pressure of the sole-attaching operation resulting not onlyin the cement attachment of the 'solemargins to 55 the shoe bottom but also in the cement attachment of theintramarglnal shank portion of the sole to the shank piece and of the shank piece itself to the shoe bottom.

It may be desirable to permit the softened shank piece covering to .dry,'at least partially, 6

before the outsole is applied and thus to provide. for a firmer attachment of the shank piece to the shoe bottom so as to insure against possibility of the shank piece being displaced during subsequentsole-attaching operations. In such acase the shank piece covering will again be softened, as by-the application of solvent thereto, Just prior to the attaching of the outsole. In cases where the shoe parts have been preliminarily prepared for adhesive attachment of the outsole 15 to the shoe as, for example, by having a coating of pyroi'wlin cement applied to the overlasted up-' per margins and to the margin of the outsole,.or by having a strip of cellulose ester braid applied, either to the sole margin or to the upper margins, in accordance with the practice disclosed in my copending application serialNo. 630,776, filed August 29, 1932, the cement coating will be activated or Y the cellulose ester braid will be softened by the application of solvent thereto before the outsole is applied. In such cases it has sometimes been found practicable to dispense with a secondapplication of solvent directly to the shank piece covering inasmuch as a suiiicient amount of solvent" will usually be squeezed or forced inwardly from the cement-coated'surfaces of the upper and outsole to insure suitable softening, of the shank piece covering. It may even be practicable to rely upon this inward displacement and outsole to soften the shank piece covering upon both sides of the shank piece so that the shank piece may be laid in place upon the shoe bottom without any preliminary application of solvent thereto, thesolvent displaced inwardly by the pressure of the sole attaching operation serving to condition the shank piece covering for the attachment of the shank piece to the shoe bottom or insole as well as to the outsole. If the shank piece is to be applied to the insole without first 46 having had its covering softened, the shank piece may be held inplace by means of tacks or other fastenings driven into the insole, such fastenings serving also as an additional means for preventing displacement of the shank piece during the wearing of the shoe. V

Considered in another aspect, the invention 7 consists in a shank piece covered with fabric capable of coacting with a solvent to produce cement thereby adapting the shank piece for use in the practice of the above-described method. The illustrated shank piece is provided with a fabricated. tubular, sheath-like covering of cellulose ester fibers. The shank piece covering may include also reinforcing threads or fibers of cotton, linen or other material which is insoluble in commercially available organic solvents and advantageously these reinforcing fibers may be secured to the shank piece by means of adhesive produced by the action of a solvent upon the cellulose ester fibers.

The invention further includes, as an article of manufacture, a tubular shank piece cover of cellulose derivative fabric.

Invention is still further to be recognized as residing in a shoe comprising an upper, a shoe bottom member, a tread sole, and a shank piece secured to the shoe bottom member and to the tread sole by a covering of cellulose derivative.

The invention in its various aspects will be described with reference to the accompanying drawing, in which Fig. l is a perspective view of a tubular shank piece covering of loosely braided cellulose ester fabric embodying a feature of the present invention;

Fig. 2 is a sectional view, on an enlarged scale, taken along the line 11-1! of Fig. 1;

Fig. 3 is a perspective view of a shank piece having a tubular covering thereon of the type shown in Fig. 1;

Fig. 4 is a sectional view on an enlarged scale taken along the line IV--IV of Fig. 3;

Fig. 5 is a perspective view of a shoe bottom prepared for the attachment of an outsole in accordance with the method of the present invention;

Fig. 6 is a perspective view of an outsole molded or conformed to fit the bottom of the shoe of Fig. 5 and prepared for cement attachment to the shoe;

Fig. 7 is a perspective view of a portion of a shoe bottom prepared for the attachment of an outsole in accordance with a' method constituting a modification of that exemplified by Fig. 5; and

Fig. 8 is a cross-sectional view of the shoe as it appears when completed. 7 I

In practising the method of my invention, as herein exemplified, a shoe bottom and an outsole are prepared in the usual manner for the cement attachment of the sole to the shoe. Thus, a shoe i0 is shown in Fig. 5 as being mounted upon a last I! and having the marginal portions ll of the upper overiasted upon an insole i8 and secured in lasted relation at the toe, for example, by cement,

at the heel seat by tacks II, and along the shank and opposite sides of the forepart by means of suitable fastenings, such as staples 20. To prepare the shoe bottom and the outsole for the reception of the cement, the overiasted upper margins ll and the marginal portions of the outsole 22 (Fig. 6) are roughened and coated with adhesive, such as pyroxylin cement, as herein indicated at 24 and 28, respectively. It is to be understood, however, that the invention is not necessarily restricted in its application to shoes having cement-attached soles but is useful also in connection with the manufacture of shoes wherein the tread soles are attached by stitching or other fastenlngs. As illustrated, the outsole 22 has been molded or conformed to fit the shoe bottom.

In acoordancewith the illustrated exemplification of m improved method I secure the intrafmarginal shank portion of the outsole to the shoe bottom by means of cement produced by the action of a solvent upon cellulose derivative d1 posed between the outsole and a shank piece 30 and between the shank piece 30 and the shoe bottom, the cellulose derivative being preferably in the form of textile fabric composed of cellulose ester fibers, such as cellulose acetate or cellulose nitrate fibers. Preferably the fibrous cellulose derivative is made in the form of a tubular sheath-like covering 32 for the shank piece, the latter being herein shown as consisting of cellulose ester fabric composed of loosely braided fibers so that an openwork covering is provided which may readily be acted upon by the solvent. Cellulose acetate fabric, for example, fabric made of the fiber available under the trade name Celanese, is particularly useful for this purpose. The cellulose ester fabric may be reinforced by fibers or strands of material, such as cotton, linen, etc., which is insoluble in the solvent used for the cellulose ester fibers. For convenience of description, the cellulose ester fibers will be referred to hereinafter as "soluble fibers, meaning fibers which are soluble in a selected solvent such as acetone, and the reinforcing fibers will be referred to as insoluble" fibers, meaning fibers which are insoluble in the particular solvent used for the cellulose ester fibers. In addition to strengthening the covering, the use of insoluble threads or fibers with the "soluble fibers reduces the cost of manufacture of the covering. Moreover, the

presence in the completed shoe of the insoluble" fibers encircling the shank piece tends to strengthen the bond between the cement and the shank piece in a manner tending to prevent the hardened cement from breaking away from the shank piece during the wearing of the shoe. Advantageously a substantial number of insoluble fibers may be employed, the fibers being braided, or otherwise fabricated, so that, after the soluble fibers have been converted into cement, the shank piec will still be enveloped by a tubular fabric covering which will tend to make even more secure and lasting the attachment of the shank piece to the shoe. The covering may be prevented from slipping off the shank piece during handling and shipment of the latter by a preliminary application to the covering of a sufilcient quantity of solvent to cause the insoluble fibers to adhere to the shank piece. Thus the shank piece may have a tubular covering of fabricated non-soluble fibers permanently secured thereto by means of cement derived from the "soluble" fibers while the latter, being in a partially converted state and remaining at least partially intact, will function, when again softened after the shank piece has been placed in a shoe, to secure the shank piece and the insoluble portion of the covering to the outer and inner soles of the shoe. It is believed that the presence, in the completed shoe, of the insoluble" fibers or threads composing the shank piece covering, will tend also to prevent squeaking of the shoe.

The tubular covering 32 may be readily applied to the shank piece 30 by slipping the covering over the shank piece in the same manner as a sheath is slipped over a knife, so as to produce a covered shank piece such as that shown in Figs. 3 and 4. In using the covered shank piece to insure additional security in the attachment of the shank portion of an outsole, the shank piece is placed in the usual position in the shoe where the covering, after being converted into a plastic cement-like mass by the action of a solvent thereon, will function both in securing the outsole to the shank stiffener and the shank stiffener to the insole.

I prefer tosoften the shank piece covering by dipping the covered shankpiece into a solvent,

so that the covering will become substantially saturated with the solvent, before the shank piece upon the insole in the space between the overlasted upper margina'as illustrated in Fig. 5. The shank piece covering being semi-plastic at this time, due to the action of the solvent thereon, the slight pressure applied by the operator in laying the shank piece will serve to stickthe' shank piece in place sufilciently to hold it against accidental displacement during the operation of shoe bottom filling and during application of the outsole. The cement coating upon the overlasted and roughened'upper margins 24 and/or upon the roughened margins 28 of the outsole 22 having been first activated by the application of solvent thereto in the customary manner, the outsole may now'be cement-attached to the shoe by the use, for examplef-of a cement sole-attaching machine of thecharacter disclosed in an application for Letters Patent of the United States, Serial No. 388,739,1flled August 27, 1929, in the name of Milton H. Ballard. The cement produced by the action of the solvent upon the shank piece covering will be forced, by the soleattaching pressure, into the form of layers interposed between the shank. stiffener and'the insole and between the shank stiffener and the outsole and, upon drying, the cement will serve effectively to secure the intramarginal shank portion of the outsole to the shoe bottom and also to reinforce and stiffen the shank portion of the shoe, without, however, interfering with the desired resilience thereof. Moreover, the cement, while plastic, will be squeezed or displaced outwardly by the sole-attaching pressure so as to fill. all spaces between the stiffener and the edges of the upper margins so that no separate filling substance will be required in the shank portion of the shoe bottom. As a result of this action the shank stiffener will be embedded in cement in the finished shoe in suchflamanner as to insure against both .endwiseand; ;latera displacement of the shank stiffener. the life of the shoe.

In commercial practice it will undoubtedly be desirable to apply the covered shank pieces to the bottoms of a plurality of shoes before attaching the outsoles to any of them, in which case the cement produced by the action of the solvent upon the shank piece coverings will be come partially or wholly dry before the shoes are ready to have the outsoles attached. Such drying of the cement is desirable inasmuch as the dried cement will serve to hold the shank pieces securely in place upon the shoe bottom so, that they have no. tendency to slip out of place during the sole-attaching operation. the cement-like covering upon the shank stiffener is permitted to dry as above indicated, it may be reactivated by the action of thesolvent applied either to the cement-coated upper margins or the outsole margins or to both the upper and outsole margins, that solvent being forced inwardly by the sole-laying pressure so as to engage and attach the shank piece covering. If desired, however, solvent may be applied directly to each shank piece covering just prior to the attaching ofthe outsole.

It may be found desirable to employ fastening means such, for example, as the tacks 34 (Fig. 7)

for securing the shank stiffener to the innersole prior'to' the application of the outersole, and in such cases it may be found practicable to secure the shank piece-in place upon the insole without having first subjected the shank piece covering to the action of solvent and to rely upon a subsequent application of solvent to the exposed portion of the shank piece covering to soften not only the exposed portion of the covering but also the portion between the shank stiffener and the insole. In fact, it has been found that sumcient solvent may be squeezed inwardly from the marginal portions of the sole and upper to soften all portions of the shank piece covering without requiring any separate or manual application of solvent to the latter. 1

As will be readily appreciated, the herein-described method of attaching the intramarginal shank portions of soles to shoes insures greater security of attachment than has been possible heretofore in cases'where there is no positive securing or'bonding together of the tread sole and the shank piece and of the shank piece to the insole. Moreover, due tothe secure attachment of the shank piece to both the inner and outer soles, and the filling in of all spaces between the soles alongthe lateral edges of the life of the shoe.- This method of attachment' of the shankfportions of soles is particularly advantageous in shoes having unusually narrow shank portions, as in so-called fiddle shank shoes, where the absence of secure attachment of the intramarginal shank portions of the tread soles has been recognized heretofore as inherent weakness of construction.

Having described my invention, what I claim as new and desire to secure by Letters Patent f the United States is: I

1. That improvement in methods of cementttaching soles to shoes which consists in securg the intramarginal shank portion of a tread sole to a shoe by means of cement produced by the action of a solvent on fibrous cellulose derivative fabric disposed between the tread soleand a shank piece attached to the shoe bottom.

2'. That improvement in methods of attaching soles to shoes which consists in securing the intramarginal shank portion of a tread sole to a shoe by means of adhesive produced by the action of a solvent on fibrous material disposed between the tread sole and a shank piece attached I to the shoe bottom.

3. That improvement in methods of cementattaching soles to shoes which consists insecuring a; shank piece to the bottom of a shoe, and securlng'the intrarnarginal shank portion'of a tread sole to'the shank piece by means of cement produced by the action of a solvent upon fibrous material applied between the shank piece and the shoe bottom andbetween the shank piece and I terial applied between the shank piece and the shoe bottom. 7

5. That improvement in methods of attaching soles to shoes which consists in disposingfibrous cellulose derivative and a solvent therefor between a tread sole and a shank piece, and applying preaure tothe sole and the shoe thereby causing the cement formed by the action of the solvent upon the cellulose derivative to stick the intro-marginal portion of the tread sole to the shank piece.

6. That improvement in methods of making shoes which comprises disposing between a shank piece and a shoe bottom and between the shank piece and an outsole fibrous cellulose derivative treated with a solvent, and applying pressure to the shoe and the sole thereby causing the cement formed by the action of the solvent on the cellulose derivative to stick the shank piece to the shoe bottom and to the outsole.

7. That improvement in methods of-making shoes which comprises applying cellulose ester fabric to both sides of a shank piece, positioning the shank piece upon the bottom of a shoe, treating the fabric with a solvent, and attaching an outsole while utilizing said treated fabric in securing the shank piece to the shoe bottom and the outsole to the shank piece.

I. That improvement in methods of cementattaching soles to shoes which comprises securing to the bottom of a shoe a shank piece having a covering of cellulose derivative fabric, treating the fabric with a solvent therefor which by acting thereon will produce cement, positioning an outsole on the shoe bottom, and applying pressure to the shoe and the sole thereby causing the cement formed by the action of the solvent on the fabric to stick the sole to the shank piece.

9. That improvement in methods of cementattaching soles to shoes which consists in covering a shank piece with cellulose ester fabric, applying a solvent to the fabric covering, applying the covered shank piece to the bottom of a shoe, positioning a tread sole upon the shoe bottom, and applying pressure to the shoe and the sole to attach the shank piece to the shoe bottom and the sole-to the shank piece.

10. That improvement in methods of attaching solesfto shoes which comprises covering a shank piece with tubular braid composed of cellulose ester fiber, dipping the covered shank piece in solvent, applying the shank piece to the shoe bottom, and cement-attaching the sole to the shoe thereby causing the shank piece to become attached to the shoe bottom and the sole to the shank piece.

11. That improvement in methods of cementattaching soles to shoes which comprises covering a shank piece with tubular cellulose acetate braid, dipping the covered shank piece in solvent, laying the shank piece in place upon the shoe bottom, allowing the softened fabric to har-i den to attach the shank piece to the shoe bottom, thereafter applying solvent 'to the exposed side of the covered shank piece. positioning an outsole on the shoe bottom, and applying pressureto the shoe and to the sole to displacethe softened fabric to fill the cavities in the shoe bottomandtoattachthesoletotheshsnkpiece and the shank pieceto bottom.

12. Tbatimprovement in methods of attaching sales to shoes which consists in applying to a shank piece a tubular covering of cellulose-deriva- 'tive fabric, applying a solvent to said fabric covering, securing the shank piece in place upon the bottom of a shoe by means of the cement produced by the action of the solvent upon said fabric, applying an outsole to the shoe, and securing the outsole to said shank piece by means of said cement.

13. That improvement in methods of attaching soles to shoes which consists in inserting a shank piece into a tubular covering of cellulose nitrate fabric, positioning the shank piece in position upon the bottom of a shoe, applying a solvent to the fabric covering, positioning an outsole upon the shoe, and applying pressure to the outsole to efiect the adhesive attachment of the shank piece to the shoe bottom and of the outsole to the shank piece by means of cement produced by the action of the solvent upon said fabric covering.

14. A shank piece covered with cellulose ester fabric.

15. A shank piece covered with fabric capable of coacting with a solvent to produce cement.

16. A shank piece covered with fabric soluble in acetone.

17. A shank piece covered with nitrocellulose fabric.

18. A shank piece covered with cellulose acetate fabric.

19. A shank piece enclosed within a tubular covering of cellulose derivative fabric.

20. A shank piece having a tubular covering of cellulose derivative fabric.

21. A shank piece having a tubular covering of cellulose'acetate fabric.

22. A shank piece having a braided tubular covering of nitrocellulose fabric.

23. A shank piece having a covering of cellulose ester fabric in loosely braided form.

24. A shank piece having a covering composed of fibers of material soluble in a selected solvent to produce an adhesive reinforced by fibers of material insoluble in said solvent.

25. A shank piece having a covering composed of cellulose derivative fibers soluble in suitable organic solvents to produce an adhesive reinforced by cellulose fibers insoluble in said solvents.

26. A shank piece having a cover of fibrous cellulose derivative soluble in a selected solvent to produce an adhesive, said cover enveloping the shank piece and being secured to it by means of adhesive.

27. A shank piece ha g a tubular covering of cellulose derivative fibers soluble in a selected solvent .to produce an adhesive and means securing said coveringto the shank piece.

28. A shank'piece having an enveloping fabricated covering composed of fibers soluble in organic solvents to produce an adhesive, and means fixedly securing said covering to the shank piece. 29..A tubular shank piece cover of cellulose derivative fabric.

' 30. A shank piece having a covering composed of material fabricated from fibers of cellulose acetate and cotton.

31. A tubular shank piece covering of textile fabric containing fibers capable of producing cement when acted upon by a solvent.

32. A fabricated shank piece cover composed of fibers of material soluble in a selected solvent to produce an adhesive and fibers of material insoluble in said solvent.

33. A shank piece having thereon an openwork adheslve-forming-covering of cellulose derivative.

MAX W. TETLOW. 

